1. Field of the Invention
The present invention relates to a solid-state image sensor, a camera, and a method of manufacturing the solid-state image sensor.
2. Description of the Related Art
A solid-state image sensor includes a microlens to condense light to a photoelectric converter. The incident angle of light to an image sensing region is larger in the peripheral portion than in the central portion of the image sensing region. Therefore, the light condensing efficiency of light to the photoelectric converter by the microlens decreases more in the peripheral portion than in the central portion of the image sensing region. This can cause shading owing to the structure of the solid-state image sensor.
Japanese Patent Laid-Open No. 06-140609 describes that as a distance from the center of an imager unit increases, an amount of shifting an on-chip lens and an intermediate layer (color filter layer) corresponding to a light receiving unit to the center of the imager unit increases.
In general, the image sensing region of the solid-state image sensor is not a square but a rectangle having long sides and short sides. Therefore, shading in a direction along the long sides and shading in a direction along the short sides are different. Conventionally, however, a microlens array taking the difference between the shading in the direction along the long sides and the shading in the direction along the short sides into consideration has not been designed. That is, conventionally, the sectional shapes of the microlens along the long sides and the short sides are the same.